The Study: Physical activity and the risk of SARS-CoV-2 infection, severe COVID-19 illness and COVID-19 related mortality in South Korea: a nationwide cohort study

Overview: This is a very large, retrospective study from South Korea which looks at the relationship between “physical activity and risk of SARS-CoV-2 infection, severe illness from COVID-19 and COVID-19 related death”.

Key Points: 

·         The study looked at 212,768 adult subjects who were tested for SARS COV-2 in early 2020. 

·         76,395 of these subjects had also completed the government’s national general health examination  in 2018-19 to assess physical activity levels within the general population. 

·         Records were compared to assess the relationship between physical activity and:

                   a. The likelihood of testing positive for SARS-CoV-2. 

                  b. The likelihood of experiencing severe Covid-19 disease. 

                  c. The likelihood of Covid-19 related death.  

·         Out of the 76 395 participants who completed the general health examination 2295 (3.0%) tested positive for SARS-CoV-2.

 ·         Of these, 446 (0.58%) experienced severe illness from COVID-19. 

·         Forty-five (0.059%) died from COVID-19. 

·         Adults who engaged in both aerobic and muscle strengthening activities had a 15% reduced likelihood of becoming infected (2.6% vs 3.1%). 

·         Were less than half as likely to experience severe illness (0.35% vs 0.66%). 

·         Were 75% less likely to die from Covid-19 (0.02% vs 0.08%). 

·         The level of activity recommended by the government (150 minutes per week of moderate intensity activity) was associated with the highest level of risk reduction.

   Author’s Conclusions: Adults who engaged in recommended levels of physical activity appeared to have decreased rates of: 1) COVID-19 infection, 2) severe COVID-19 disease and 3) COVID-19 related death. “Our findings suggest that engaging in physical activity has substantial public health value and demonstrates potential benefits to combat COVID-19.”

 “Encouraging individuals to maintain recommended levels of physical activity during the COVID-19 pandemic should be promptly and vigorously considered at the public health level.”

 Reviewer's Comments: 

First, the South Korean government actually had the foresight to assess physical activity levels in a large segment of their population! We could use that kind of forward thinking here in the U.S. Second, the increased risks of COVID related death and severe disease posed by comorbidities such as obesity, high blood pressure, diabetes, metabolic syndrome etc are well known. And third, these are for the most part, lifestyle related health issues. 

In the face of all we know, why on earth do we not have a national P.R. program encouraging people to get physically active? Thirty minutes a day, five days a week to live. Sound like a deal to me.

 Reviewer:  Mark R. Payne DC

 Reference: Seung Won Lee ,Jinhee Lee, Sung Yong Moon, Hyun Young Jin, Jee Myung Yang, et al.  Physical activity and the risk of SARS-CoV-2 infection, severe COVID-19 illness and COVID-19 related mortality in South Korea: a nationwide cohort study. BMJ. Br J Sports Med 2021;0:1–13. doi:10.1136/bjsports-2021-104203

 Link To Full Text: https://bjsm.bmj.com/content/bjsports/early/2021/07/21/bjsports-2021-104203.full.pdf